hose for belly press

[Allan Gilreath, RPT]

Maybe not a bull’s eye but be sure to stay out of the line of fire. <grin> I
think we only went up to 100psi on leak tests (not that we use near that
much for pressing.) We also used a rubber gasket between the fire hose and
the end caps to give more grip (they really wanted to slide out of the
synthetic fire hose!) You’ve definitely embarked on an adventure! Making the
curved cauls and the backing braces proved interesting too. It’s quite a bit
of pressure over the distance of a long rub.

 

Allan

Allan L. Gilreath, RPT

  _____  

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Will Truitt
Sent: Saturday, September 27, 2008 3:18 PM
To: 'Pianotech List'
Subject: RE: hose for belly press

 

Thanks to Ron, Dale, and Allan here for sharing their experiences and
materials regarding belly press hose.  I will see if I can find a reasonably
local supplier for fire hose – I hadn’t considered that aspect.

 

Ouch!!  Oomph!  Urnhh!   That’s the sound of me kicking myself in the butt
for buying cheap crap from Home Depot for $30.  I took the hoses apart
today, and the rubber hose had already permanently expanded to a larger
diameter after only a couple of inflations to 40 PSI, and clearly the
markings of the hose clamps meant it wouldn’t last long anyway.  

 

I can give myself a little pat on the back though.  None of the end caps at
any of the fittings leaked – only the hose itself.  I did spend good money
and didn’t chintz on those items, and put them together very carefully with
the Teflon tape and severe tightening.  So, with the right hose, I think
I’ll be in good shape.  

 

Allan – should I set up a bulls-eye across the room and get in a  little
target practice?  None of mine shot across the room when I was testing.  Now
I’m disappointed.  

 

Will Truitt

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Allan Gilreath, RPT
Sent: Saturday, September 27, 2008 12:06 PM
To: Pianotech List
Subject: Re: hose for belly press

 

Good afternoon Will,

As you've seen, firehose seems to work best for most of us. I've pressed
quite a few boards with mine now and, although I keep changing other aspects
of the design, the firehose works great. I use pvc end caps with multiple
hose clamps around them. On the end that connects to the air supply we use a
pvc end cap with a Legris bulkhead fitting. This allows for a self-sealing
attachment to a 4mm supply line with tee junctions. This way we can spread
up glue and clamp one rib at a time. The 4mm hose allows for a relatively
slow fill and release the pressure. Another nice thing about it is that you
can even use a hemostat to clamp off a section. I leave mine pressed
overnight and connected to the compressor just in case there are any leaks.
In coming up with system to seal off the ends of the hose, we actually shot
a couple of the end caps across the shop so be cautious with the setup. 

We got the hose as the cut-offs from a local fire equipment supplier since
the lengths that we need are so short.

Hopefully this will help get you started. 

Allan
Allan Gilreath, RPT

Will Truitt wrote: 

To the bellymen on Pianotech Forum:

 

I have built a set of cauls for gluing ribs to the panel using air pressure.
I discovered yesterday that the 1 ½” rubber hose that I bought from Home
Depot is most decidedly not ready for prime time – no matter how much I
tighten the hose clamps on the hose at the ends, air still bleeds out at an
alarming rate (easy to see when you inflate the hose and stick the end into
a pail of water).  After discussion by phone yesterday with Jude Reveley, I
am confident that the material is inadequate.  Pressure ratings aside, it
simply is not substantial enough to resist the air pressure.  

 

Jude has recommended a ribbed nitrile/PVC hose, which is what he is using in
his setup with good success.  I am looking for a source for such that I can
quickly order it online, hopefully in smaller quantities.  

 

I would also consider other hose materials that our bellymen are using with
good success and reliability.  

 

Thanks in advance for anything you share

 

Will Truitt

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20080927/68d78f6c/attachment.html